Featured Research

Brain disease scientists may need to look beyond nerve cells and start paying attention to the star-shaped cells known as 'astrocytes,' because they play specialized roles in the development and maintenance of nerve circuits, and may contribute to a wide range of disorders, according to a new study. The researchers discovered in mice that a particular form of astrocyte within the spinal cord secretes a protein needed for survival of the nerve circuitry that controls reflexive movements. This discovery is the first demonstration that different types of astrocytes exist to support development and survival of distinct nerve circuits at specific locations within the central nervous system.

Share This

Scientists studying brain diseases may need to look beyond nerve cells and start paying attention to the star-shaped cells known as "astrocytes," because they play specialized roles in the development and maintenance of nerve circuits and may contribute to a wide range of disorders, according to a new study by UC San Francisco researchers.

Related Articles

In a study published online April 28, 2014 in Nature, the researchers report that malfunctioning astrocytes might contribute to neurodegenerative disorders such as Lou Gehrig's disease (ALS), and perhaps even to developmental disorders such as autism and schizophrenia.

David Rowitch, MD, PhD, UCSF professor of pediatrics and neurosurgery and a Howard Hughes Medical Institute investigator, led the research.

The researchers discovered in mice that a particular form of astrocyte within the spinal cord secretes a protein needed for survival of the nerve circuitry that controls reflexive movements. This discovery is the first demonstration that different types of astrocytes exist to support development and survival of distinct nerve circuits at specific locations within the central nervous system.

Astrocytes vastly outnumber signal-conducting neurons, and make up the majority of cells in the brain. But where neuroscientists are accustomed to seeing only vanilla when it comes to astrocytes -- viewing all of them as similar despite their different locations in brain and spinal cord -- they now will have to imagine "31 flavors" or more.

There might even be hundreds of distinctive varieties of astrocytes performing specific functions in different locations, according to Rowitch, chief of neonatology for UCSF Benioff Children's Hospital San Francisco.

"Our study shows roles for specialized astrocytes that function to support particular kinds of neurons in their neighborhood," Rowitch said.

Led by Rowitch lab postdoctoral fellow Anna Molofsky, MD, PhD, the researchers studied the spinal cord sensory motor circuit, which allows both mice and humans to react without thought -- to jerk a limb away from something hot, for instance.

The team discovered that a protein called Sema3a is produced much more abundantly by astrocytes close to motor neurons than by astrocytes from other regions in the spinal cord. They concluded that motor neurons required this source of Sema3a from the local astrocytes, because when Sema3a production was blocked, the motor neurons failed to form normal connections, and half of them died.

Motor neurons also die in ALS, a fatal neurodegenerative disease, and in spinal muscular atrophy, a disease that can affect newborn infants. In other studies, scientists have found that abnormal astrocytes can have toxic effects on motor neurons.

Molofsky is a psychiatrist who studies how astrocytes organize nerve circuits, and how disruptions of these nerve circuits during development or disease may involve abnormal astrocyte function. Disrupted neural circuits are believed to be responsible for certain psychiatric disorders.

"The immediate implications of this study are for diseases of motor neurons, like ALS, but I think our findings might also apply more generally to diseases of neural-circuit formation in the brain such as autism, schizophrenia and epilepsy," Molofsky said. "To achieve a comprehensive understanding of how neural circuits form and are maintained, it seems important that we integrate knowledge of how astrocytes support that process."

Rowitch agrees. "To the extent that psychiatric or neurological disease is localized to a specific part of the brain, we should now be considering the potentially specialized type of astrocytes regulating nerve connections in that region and their contributions to disease," he said.

More From ScienceDaily

More Health & Medicine News

Featured Research

Mar. 31, 2015  Researchers have recorded the first direct observations of the micro-scale mechanisms behind the ability of skin to resist tearing. The results could be applied to the improvement of artificial skin, ... full story

Mar. 31, 2015  Fewer than half of the physicians trained in the United States in 2013 received formal education or training on the subject of exercise, according to new research. "There are immense medical benefits ... full story

Mar. 31, 2015  Memory and as well as connections between brain cells were restored in mice with a model of Alzheimer's given an experimental cancer drug, researchers report. "With this treatment, cells under ... full story

Mar. 31, 2015  Increasing state alcohol taxes could prevent thousands of deaths a year from car crashes, say researchers, who found alcohol-related motor vehicle crashes decreased after taxes on beer, wine and ... full story

Mar. 31, 2015  Alcoholism takes a toll on every aspect of a person's life, including skin problems. Now, a new research report helps explain why this happens and what might be done to address it. "The clinical ... full story

Mar. 31, 2015  A new population of 'memory' immune cells has been discovered by scientists, throwing light on what the body does when it sees a microbe for the second time. This insight, and others like it, will ... full story

Mar. 31, 2015  Coronary heart disease and stroke, two of the leading causes of death in the United States, are diseases associated with heightened platelet reactivity. A new study in humans suggests an underlying ... full story

Mar. 31, 2015  A new study had researchers seeking answers to why the therapeutic benefit afforded by SSRIs was so limited in children and teenagers. If researchers can uncover the biological mechanisms preventing ... full story

Mar. 31, 2015  A drug being developed to treat osteoporosis may also be useful for treating osteogenesis imperfecta or brittle bone disease, a rare but potentially debilitating bone disorder that that is present ... full story

Featured Videos

Solitair Device Aims to Takes Guesswork out of Sun Safety

Reuters - Innovations Video Online (Mar. 31, 2015)  The Solitair device aims to take the confusion out of how much sunlight we should expose our skin to. Small enough to be worn as a tie or hair clip, it monitors the user&apos;s sun exposure by taking into account their skin pigment, location and schedule. Matthew Stock reports.
Video provided by Reuters

Soda, Salt and Sugar: The Next Generation of Taxes

Washington Post (Mar. 30, 2015)  Denisa Livingston, a health advocate for the Dinι Community Advocacy Alliance, and the Post&apos;s Abby Phillip discuss efforts around the country to make unhealthy food choices hurt your wallet as much as your waistline.
Video provided by Washington Post

S. Leone in New Anti-Ebola Lockdown

AFP (Mar. 28, 2015)  Sierra Leone imposed a three-day nationwide lockdown Friday for the second time in six months in a bid to prevent a resurgence of the deadly Ebola virus. Duration: 01:17
Video provided by AFP

Related Stories

Oct. 10, 2014  A previously unknown mechanism through which the brain produces new nerve cells after a stroke has been discovered by researchers. A stroke is caused by a blood clot blocking a blood vessel in the ... full story

Aug. 7, 2012  Epileptic fits are like thunderstorms raging in the brain: Nerve cells excite each other in an uncontrolled way so that strong, rhythmic electrical discharges sweep over whole brain regions. In the ... full story

Aug. 24, 2010  When human umbilical cord blood cells were used to treat cultured rat brain cells deprived of oxygen, the cells appeared to protect astrocytes from cell death after stroke-like damage. Researchers ... full story

June 14, 2010  Astrocytes are the most common type of cell in the brain and play an important role in the function of neurons -- nerve cells. New research from Sweden shows that they are also directly involved in ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.